Identification of viral sequences on chromosomes will be accomplished by hybridizing ASV-specific cDNA synthesized in tirol using 5-methyl dCTP as precursor instead of dCTP, reacting with antibodies directed against 5-methyl cytidine conjugated bovine serum albumin following depurination and finally visualizing the antibody by an indirect immunoperoxidase technique. Purification of cellular sequences that are involved in viral DNA integration will be achieved by hybridizing partially enriched cellular DNA fragments, generated by restriction enzymes, with virion RNA, separation of hybrids from unhybridized sequences in equilibrium density gradient. Finally, the sequences will be radiolabeled with polymerase and further purified in equilibrium gradients.